Biaxially textured articles formed by powder metallurgy

ABSTRACT

A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100}&lt;100&gt; orientation texture; and further having a Curie temperature less than that of pure Ni.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a divisional application of U.S. patentapplication Ser. No. 09/931,201 entitled Biaxially Textured ArticlesFormed by Powder Metallurgy, filed on Aug. 16, 2001, hereby incorporatedby reference, which is a divisional application of U.S. patentapplication Ser. No. 09/570,289 entitled Biaxially Textured ArticlesFormed by Powder Metallurgy, filed on May 15, 2000, which issued as U.S.Pat. No. 6,331,199 on Dec. 18, 2001, hereby incorporated by reference.

[0002] The following relate to the present invention and are herebyincorporated by reference: U.S. patent application Ser. No. 09/571,561Method for Forming Biaxially Textured Articles by Powder Metallurgy byGoyal, filed on May 15, 2000; U.S. Pat. No. 5,739,086 Structures HavingEnhanced Biaxial Texture and Method of Fabricating Same by Goyal et al.,issued Apr. 14, 1998; U.S. Pat. No. 5,741,377 Structures Having EnhancedBiaxial Texture and Method of Fabricating Same by Goyal et al., issuedApr. 21, 1998; U.S. Pat. No. 5,898,020 Structures Having biaxial Textureand Method of Fabricating Same by Goyal et al., issued Apr. 27, 1999;U.S. Pat. No. 5,958,599 Structures Having Enhanced Biaxial Texture byGoyal et al., issued Sep. 28, 1999; U.S. Pat. No. 5,964,966 Method ofForming Biaxially Textured Substrates and Devices Thereon by Goyal etal., issued Oct. 21, 1999; and U.S. Pat. No. 5,968,877 High Tc YBCOSuperconductor Deposited on Biaxially Textured Ni Substrate by Budai etal., issued Oct. 19, 1999.

[0003] This invention was made with Government support under ContractNo. DE-AC05-96OR22464 awarded by the United States Department of Energy.The Government has certain rights in this invention.

FIELD OF THE INVENTION

[0004] The present invention relates to biaxially textured metallicsubstrates and articles made therefrom, and more particularly to suchsubstrates and articles made from high purity face-centered cubic (FCC)materials using powder metallurgy techniques to form long lengths ofbiaxially textured sheets, and more particularly to the use of saidbiaxially textured sheets as templates to grow epitaxialmetal/alloy/ceramic layers.

BACKGROUND OF THE INVENTION

[0005] Current materials research aimed at fabricating high-temperaturesuperconducting ceramics in conductor configurations for bulk, practicalapplications, is largely focused on powder-in-tube methods. Such methodshave proved quite successful for the Bi—(Pb)—Sr—Ca—Cu—O (BSCCO) familyof superconductors due to their unique mica-like mechanical deformationcharacteristics. In high magnetic fields, this family of superconductorsis generally limited to applications below 30K. In the Re—Ba—Cu—O(ReBCO, Re denotes a rare earth element), Tl—(Pb,Bi)—Sr—(Ba)—Ca—Cu—O andHg—(Pb)—Sr—(Ba)—Ca—Cu—O families of superconductors, some of thecompounds have much higher intrinsic limits and can be used at highertemperatures.

[0006] It has been demonstrated that these superconductors possess highcritical current densities (J_(c)) at high temperatures when fabricatedas single crystals or in essentially single-crystal form as epitaxialfilms on single crystal substrates such as SrTiO₃ and LaAlO₃. Thesesuperconductors have so far proven intractable to conventional ceramicsand materials processing techniques to form long lengths of conductorwith J_(c) comparable to epitaxial films. This is primarily because ofthe “weak-link” effect.

[0007] It has been demonstrated that in ReBCO, biaxial texture isnecessary to obtain high transport critical current densities. HighJ_(c)'s have been reported in polycrystalline ReBCO in thin filmsdeposited on special substrates on which a biaxially texturednon-superconducting oxide buffer layer is first deposited using ion-beamassisted deposition (IBAD) techniques. IBAD is a slow, expensiveprocess, and difficult to scale up for production of lengths adequatefor many applications.

[0008] High J_(c)'s have also been reported in polycrystalline ReBCOmelt-processed bulk material which contains primarily small angle grainboundaries. Melt processing is also considered too slow for productionof practical lengths.

[0009] Thin-film materials having perovskite-like structures areimportant in superconductivity, ferroelectrics, and electro-optics. Manyapplications using these materials require, or would be significantlyimproved by, single crystal, c-axis oriented perovskite-like films grownon single-crystal or highly aligned metal or metal-coated substrates.

[0010] For instance, Y—Ba₂—Cu₃—O_(x) (YBCO) is an importantsuperconducting material for the development of superconducting currentleads, transmission lines, motor and magnetic windings, and otherelectrical conductor applications. When cooled below their transitiontemperature, superconducting materials have no electrical resistance andcarry electrical current without heating up. One technique forfabricating a superconducting wire or tape is to deposit a YBCO film ona metallic substrate. Superconducting YBCO has been deposited onpolycrystalline metals in which the YBCO is c-axis oriented, but notaligned in-plane. To carry high electrical currents and remainsuperconducting, however, the YBCO films must be biaxially textured,preferably c-axis oriented, with essentially no large-angle grainboundaries, since such grain boundaries are detrimental to thecurrent-carrying capability of the material. YBCO films deposited onpolycrystalline metal substrates do not generally meet this criterion.

[0011] The present invention provides a method for fabricating biaxiallytextured sheets of alloy substrates with desirable compositions. Thisprovides for applications involving epitaxial devices on such alloysubstrates. The alloys can be thermal expansion and lattice parametermatched by selecting appropriate compositions. They can then beprocessed according to the present invention, resulting in devices withhigh quality films with good epitaxy and minimal microcracking.

[0012] The terms “process”, “method”, and “technique” are usedinterchangeably herein.

[0013] For further information, refer to the following publications:

[0014] 1. K. Sato, et al., “High-J_(c) Silver-Sheathed Bi-BasedSuperconducting Wires”, IEEE Transactions on Magnetics, 27 (1991) 1231.

[0015] 2. K. Heine, et al., “High-Field Critical Current Densities inBi₂Sr₂Ca₁Cu₂O_(8+x)/Ag Wires”, Applied Physics Letters, 55 (1991) 2441.

[0016] 3. R. Flukiger, et al., “High Critical Current Densities inBi(2223)/Ag tapes”, Superconductor Science & Technology 5, (1992) S61.

[0017] 4. D. Dimos et al., “Orientation Dependence of Grain-BoundaryCritical Currents in Y₁Ba₂Cu₃O⁷⁻* Bicrystals”, Physical Review Letters,61 (1988) 219.

[0018] 5. D. Dimos et al., “Superconducting Transport Properties ofGrain Boundaries in Y₁Ba₂Cu₃O₇ Bicrystals”, Physical Review B, 41 (1990)4038.

[0019] 6. Y. Iijima, et al., “Structural and Transport Properties ofBiaxially Aligned YBa₂Cu₃O_(7−x) Films on Polycrystalline Ni-Based Alloywith Ion-Beam Modified Buffer Layers”, Journal of Applied Physics, 74(1993) 1905.

[0020] 7. R. P. Reade, et al. “Laser Deposition of biaxially texturedYttria-Stabilized Zirconia Buffer Layers on Polycrystalline MetallicAlloys for High Critical Current Y—Ba—Cu—O Thin Films”, Applied PhysicsLetters, 61 (1992) 2231.

[0021] 8. D. Dijkkamp et al., “Preparation of Y—Ba—Cu OxideSuperconducting Thin Films Using Pulsed Laser Evaporation from High TcBulk Material,” Applied Physics Letters, 51, 619 (1987).

[0022] 9. S. Mahajan et al., “Effects of Target and Template Layer onthe Properties of Highly Crystalline Superconducting a-Axis Films ofYBa₂Cu₃O_(7−x) by DC-Sputtering,” Physica C, 213, 445 (1993).

[0023] 10. A. Inam et al., “A-axis Oriented EpitaxialYBa₂Cu₃O_(7−x)—PrBa₂Cu₃O_(7−x) Heterostructures,” Applied PhysicsLetters, 57, 2484 (1990).

[0024] 11. R. E. Russo et al., “Metal Buffer Layers and Y—Ba—Cu—O ThinFilms on Pt and Stainless Steel Using Pulsed Laser Deposition,” Journalof Applied Physics, 68, 1354 (1990).

[0025] 12. E. Narumi et al., “Superconducting YBa₂Cu₃O_(6.8) Films onMetallic Substrates Using In Situ Laser Deposition,” Applied PhysicsLetters, 56, 2684 (1990).

[0026] 13. R. P. Reade et al., “Laser Deposition of Biaxially TexturedYttria-Stabilized Zirconia Buffer Layers on Polycrystalline MetallicAlloys for High Critical Current Y—Ba—Cu—O Thin Films,” Applied PhysicsLetters, 61, 2231 (1992).

[0027] 14. J. D. Budai et al., “In-Plane Epitaxial Alignment ofYBa₂Cu₃O_(7−x) Films Grown on Silver Crystals and Buffer Layers,”Applied Physics Letters, 62, 1836 (1993).

[0028] 15. T. J. Doi et al., “A New Type of Superconducting Wire;Biaxially Oriented Tl₁(Ba_(0.8)Sr_(0.2))₂Ca₂Cu₃O₉ on {100}<100> TexturedSilver Tape,” Proceedings of 7th International Symposium onSuperconductivity, Fukuoka, Japan, Nov. 8-11, 1994.

[0029] 16. D. Forbes, Executive Editor, “Hitachi Reports 1-meter Tl-1223Tape Made by Spray Pyrolysis”, Superconductor Week, Vol. 9, No. 8, Mar.6, 1995.

[0030] 17. Recrystallization, Grain Growth and Textures, Paperspresented at a Seminar of the American Society for Metals, Oct. 16 and17, 1965, American Society for Metals, Metals Park, Ohio.

OBJECTS OF THE INVENTION

[0031] Accordingly, it is an object of the present invention to providenew and useful biaxially textured metallic substrates and articles madetherefrom.

[0032] It is another object of the present invention to provide suchbiaxially textured metallic substrates and articles made therefrom byrolling and recrystallizing high purity face-centered cubic materials toform long lengths of biaxially textured sheets.

[0033] It is yet another object of the present invention to provide forthe use of said biaxially textured sheets as templates to grow epitaxialmetal/alloy/ceramic layers. Further and other objects of the presentinvention will become apparent from the description contained herein.

SUMMARY OF THE INVENTION

[0034] In accordance with one aspect of the present invention, theforegoing and other objects are achieved by a biaxially textured alloyarticle having a magnetism less than pure Ni which comprises a rolledand annealed compacted and sintered powder-metallurgy preform article,the preform article having been formed from a powder mixture selectedfrom the group of binary mixtures consisting of: between 99 at % and 80at % Ni powder and between 1 at % and 20 at % Cr powder; between 99 at %and 80 at % Ni powder and between 1 at % and 20 at % W powder; between99 at % and 80 at % Ni powder and between 1 at % and 20 at % V powder;between 99 at % and 80 at % Ni powder and between 1 at % and 20 at % Mopowder; between 99 at % and 60 at % Ni powder and between 1 at % and 40at % Cu powder; between 99 at % and 80 at % Ni powder and between 1 at %and 20 at % Al powder; the article having a fine and homogeneous grainstructure; and having a dominant cube oriented {100}<100> orientationtexture; and further having a Curie temperature less than that of pureNi.

[0035] In accordance with a second aspect of the present invention, theforegoing and other objects are achieved by a biaxially textured alloyarticle having a magnetism less than pure Ni which comprises a rolledand annealed compacted and sintered powder-metallurgy preform article,the preform article having been formed from a powder mixture selectedfrom the group of ternary mixtures consisting of: Ni powder, Cu powder,and Al powder; Ni powder, Cr powder, and Al powder; Ni powder, W powderand Al powder; Ni powder, V powder, and Al powder; Ni powder, Mo powder,and Al powder; the article having a fine and homogeneous grainstructure; and having a dominant cube oriented {100}<100> orientationtexture; and further having a Curie temperature less than that of pureNi.

[0036] In accordance with a third aspect of the present invention, theforegoing and other objects are achieved by a biaxially textured alloyarticle alloy article having a magnetism less than pure Ni whichcomprises a rolled and annealed compacted and sintered powder-metallurgypreform article, the preform article having been formed from a powdermixture selected from the group of mixtures consisting of: at least 60at % Ni powder and at least one of Cr powder, W powder, V powder, Mopowder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, and REpowder; the article having a fine and homogeneous grain structure; andhaving a dominant cube oriented {100}<100> orientation texture; andfurther having a Curie temperature less than that of pure Ni.

[0037] In accordance with a fourth aspect of the present invention, theforegoing and other objects are achieved by a strengthened, biaxiallytextured alloy article having a magnetism less than pure Ni whichcomprises a rolled and annealed, compacted and sinteredpowder-metallurgy preform article, the preform article having beenformed from a powder mixture selected from the group of mixturesconsisting of: Ni, Ag, Ag—Cu, Ag—Pd, Ni—Cu, Ni—V, Ni—Mo, Ni—Al,Ni—Cr—Al, Ni—W—Al, Ni—V—Al, Ni—Mo—Al, Ni—Cu—Al; and at least one finepowder such as but not limited to Al₂O₃, MgO, YSZ, CeO₂, Y₂O_(3,), andYSZ; the article having a grain size which is fine and homogeneous andfurther having a dominant cube oriented {100}<100> orientation texture;and further having a Curie temperature less than that of pure Ni.

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In the drawings:

[0039]FIG. 1 shows a (111) pole figure for a Ni-9 at % W alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The pole figure indicates only four peaks consistentwith only a well-developed {100}<100>, biaxial cube texture. The finalannealing temperature of the sample was 1200° C.

[0040]FIG. 2 shows a phi (φ) scan of the [111] reflection, with φvarying from 0° to 360°, for a Ni-9 at % W alloy fabricated by rollingand annealing a compacted and sintered, powder metallurgy preform. Thepresence of four peaks is with only a well-developed {100}<100>, biaxialcube texture is apparent. The final annealing temperature of the samplewas 1200° C. The FWHM of the φ-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜8.8°. The FWHM of the peaks in this scanis indicative of the in-plane texture of the grains in the sample.

[0041]FIG. 3 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked in the rolling direction, for a Ni-9 at % W alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The final annealing temperature of the sample was1200° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜6.1°.

[0042]FIG. 4 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked about the rolling direction, for a Ni-9 at % W alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The final annealing temperature of the sample was1200° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜8.5°.

[0043]FIG. 5 shows a (111) pole figure for a Ni-9 at % W alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The pole figure indicates only four peaks consistentwith only a well-developed {100}<100>, biaxial cube texture. The finalannealing temperature of the sample was 1400° C.

[0044]FIG. 6 shows a phi (φ) scan of the [111] reflection, with φvarying from 0° to 360°, for a Ni-9 at % W alloy fabricated by rollingand annealing a compacted and sintered, powder metallurgy preform. Thepresence of four peaks is with only a well-developed {100}<100>, biaxialcube texture is apparent. The final annealing temperature of the samplewas 1400° C. The FWHM of the φ-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜5.80°. The FWHM of the peaks in this scanis indicative of the in-plane texture of the grains in the sample.

[0045]FIG. 7 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked in the rolling direction, for a Ni-9 at % W alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The final annealing temperature of the sample was1400° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜4.3°.

[0046]FIG. 8 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked about the rolling direction, for a Ni-9 at % W alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The final annealing temperature of the sample was1400° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜7.4°.

[0047]FIG. 9 shows a (111) pole figure for a Ni-13 at % Cr alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The pole figure indicates only four peaks consistentwith only a well-developed {100}<100>, biaxial cube texture. The finalannealing temperature of the sample was 1200° C.

[0048]FIG. 10 shows a phi (φ) scan of the [111] reflection, with φvarying from 0° to 360°, for a Ni-13 at % Cr alloy fabricated by rollingand annealing a compacted and sintered, powder metallurgy preform. Thepresence of four peaks is with only a well-developed {100}<100>, biaxialcube texture is apparent. The final annealing temperature of the samplewas 1200° C. The FWHM of the φ-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜8.7°. The FWHM of the peaks in this scanis indicative of the in-plane texture of the grains in the sample.

[0049]FIG. 11 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked in the rolling direction, for a Ni-13 at % Cr alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The final annealing temperature of the sample was1200° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜5.8°.

[0050]FIG. 12 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked about the rolling direction, for a Ni-13 at % Cralloy fabricated by rolling and annealing a compacted and sintered,powder metallurgy preform. The final annealing temperature of the samplewas 1200° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜9.8°.

[0051]FIG. 13 shows a (111) pole figure for a Ni-13 at % Cr alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The pole figure indicates only four peaks consistentwith only a well-developed {100}<100>, biaxial cube texture. The finalannealing temperature of the sample was 1400° C.

[0052]FIG. 14 shows a phi (φ) scan of the [111] reflection, with φvarying from 0° to 360°, for a Ni-13 at % Cr alloy fabricated by rollingand annealing a compacted and sintered, powder metallurgy preform. Thepresence of four peaks is with only a well-developed {100}<100>, biaxialcube texture is apparent. The final annealing temperature of the samplewas 1400° C. The FWHM of the φ-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜6.1°. The FWHM of the peaks in this scanis indicative of the in-plane texture of the grains in the sample.

[0053]FIG. 15 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked in the rolling direction, for a Ni-13 at % Cr alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The final annealing temperature of the sample was1400° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜4.5°.

[0054]FIG. 16 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked about the rolling direction, for a Ni-13 at % Cralloy fabricated by rolling and annealing a compacted and sintered,powder metallurgy preform. The final annealing temperature of the samplewas 1400° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜7.3°.

[0055]FIG. 17 shows a (111) pole figure for a Ni-0.03 at % Mg alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The Mg is predominantly expected to be present asMgO. The pole figure indicates only four peaks consistent with only awell-developed {100}<100>, biaxial cube texture. The final annealingtemperature of the sample was 1200° C.

[0056]FIG. 18 shows a phi (φ) scan of, the [111] reflection, with φvarying from 0° to 360°, for a Ni-0.03 at % Mg alloy fabricated byrolling and annealing a compacted and sintered, powder metallurgypreform. The presence of four peaks is with only a well-developed{100}<100>, biaxial cube texture is apparent. The final annealingtemperature of the sample was 1200° C. The FWHM of the φ-scan, asdetermined by fitting a gaussian curve to one of the peaks is ˜7.7°. TheFWHM of the peaks in this scan is indicative of the in-plane texture ofthe grains in the sample.

[0057]FIG. 19 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked in the rolling direction, for a Ni-0.03 at % Mgalloy fabricated by rolling and annealing a compacted and sintered,powder metallurgy preform. The final annealing temperature of the samplewas 1200° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜7.8°.

[0058]FIG. 20 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked about the rolling direction, for a Ni-0.03 at % Mg.The final annealing temperature of the sample was 1200° C. The peak isindicative of the out-of-plane texture of the sample. The FWHM of theω-scan, as determined by fitting a gaussian curve to one of the peaks is˜9.2°.

[0059]FIG. 21 shows a (111) pole figure for a Ni-9 at % W-0.03 at % Mgalloy fabricated by rolling and annealing a compacted and sintered,powder metallurgy preform. The Mg is predominantly expected to bepresent as MgO. The pole figure indicates only four peaks consistentwith only a well-developed {100}<100>, biaxial cube texture. The finalannealing temperature of the sample was 1200° C.

[0060]FIG. 22 shows a phi (φ) scan of the [111] reflection, with φvarying from 0° to 360°, for a Ni-9 at % W-0.03% Mg alloy fabricated byrolling and annealing a compacted and sintered, powder metallurgypreform. The presence of four peaks is with only a well-developed{100}<100>, biaxial cube texture is apparent. The final annealingtemperature of the sample was 1200° C. The FWHM of the φ-scan, asdetermined by fitting a gaussian curve to one of the peaks is ˜9.1°. TheFWHM of the peaks in this scan is indicative of the in-plane texture ofthe grains in the sample.

[0061]FIG. 23 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked in the rolling direction, for a Ni-9 at % W-0.03% Mgalloy fabricated by rolling and annealing a compacted and sintered,powder metallurgy preform. The final annealing temperature of the samplewas 1200° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜7.2°.

[0062]FIG. 24 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked about the rolling direction, for a Ni-9 at % W-0.03at % Mg alloy fabricated by rolling and annealing a compacted andsintered, powder metallurgy preform. The final annealing temperature ofthe sample was 1200° C. The peak is indicative of the out-of-planetexture of the sample. The FWHM of the ω-scan, as determined by fittinga gaussian curve to one of the peaks is ˜9.1°.

[0063]FIG. 25 shows a (111) pole figure for a Ni-9 at % W-0.03 at % Mgalloy fabricated by rolling and annealing a compacted and sintered,powder metallurgy preform. The Mg is predominantly expected to bepresent as MgO. The pole figure indicates only four peaks consistentwith only a well-developed {100}<100>, biaxial cube texture. The finalannealing temperature of the sample was 1400° C.

[0064]FIG. 26 shows a phi (φ) scan of the [111] reflection, with φvarying from 0° to 360°, for a Ni-9 at % W-0.03 at % Mg alloy fabricatedby rolling and annealing a compacted and sintered, powder metallurgypreform. The presence of four peaks is with only a well-developed{100}<100>, biaxial cube texture is apparent. The final annealingtemperature of the sample was 1400° C. The FWHM of the φ-scan, asdetermined by fitting a gaussian curve to one of the peaks is ˜6.1°. TheFWHM of the peaks in this scan is indicative of the in-plane texture ofthe grains in the sample.

[0065]FIG. 27 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked in the rolling direction, for a Ni-9 at % W-0.03 at% Mg alloy fabricated by rolling and annealing a compacted and sintered,powder metallurgy preform. The final annealing temperature of the samplewas 1400° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜6.7°.

[0066]FIG. 28 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked about the rolling direction, for a Ni-9 at % W-0.03at % Mg alloy fabricated by rolling and annealing a compacted andsintered, powder metallurgy preform. The final annealing temperature ofthe sample was 1400° C. The peak is indicative of the out-of-planetexture of the sample. The FWHM of the ω-scan, as determined by fittinga gaussian curve to one of the peaks is ˜7.5°.

[0067]FIG. 29 shows a (111) pole figure for a Ni-13 at % Cr-0.03 at % Mgalloy fabricated by rolling and annealing a compacted and sintered,powder metallurgy preform. The Mg is predominantly expected to bepresent as MgO. The pole figure indicates only four peaks consistentwith only a well-developed {100}<100>, biaxial cube texture. The finalannealing temperature of the sample was 1200° C.

[0068]FIG. 30 shows a phi (φ) scan of the [111] reflection, with φvarying from 0° to 360°, for a Ni-13 at % Cr-0.03 at % Mg alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The presence of four peaks with only awell-developed {100}<100>, biaxial cube texture is apparent. The finalannealing temperature of the sample was 1200° C. The FWHM of the φ-scan,as determined by fitting a gaussian curve to one of the peaks is ˜8.1°.The FWHM of the peaks in this scan is indicative of the in-plane textureof the grains in the sample.

[0069]FIG. 31 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked in the rolling direction, for a Ni-13 at % Cr-0.03at % Mg alloy fabricated by rolling and annealing a compacted andsintered, powder metallurgy preform. The final annealing temperature ofthe sample was 1200° C. The peak is indicative of the out-of-planetexture of the sample. The FWHM of the ω-scan, as determined by fittinga gaussian curve to one of the peaks is ˜5.1°.

[0070]FIG. 32 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked about the rolling direction, for a Ni-13 at %Cr-0.03 at % Mg alloy fabricated by rolling and annealing a compactedand sintered, powder metallurgy preform. The final annealing temperatureof the sample was 1200° C. The peak is indicative of the out-of-planetexture of the sample. The FWHM of the ω-scan, as determined by fittinga gaussian curve to one of the peaks is ˜9.5°.

[0071]FIG. 33 shows a (111) pole figure for a Ni-13 at % Cr-0.03 at % Mgalloy fabricated by rolling and annealing a compacted and sintered,powder metallurgy preform. The Mg is predominantly expected to bepresent as MgO. The pole figure indicates only four peaks consistentwith only a well-developed {100}<100>, biaxial cube texture. The finalannealing temperature of the sample was 1400° C.

[0072]FIG. 34 shows a phi (φ) scan of the [111] reflection, with φvarying from 0° to 360°, for a Ni-13 at % Cr-0.03 at % Mg alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The presence of four peaks is with only awell-developed {100}<100>, biaxial cube texture is apparent. The finalannealing temperature of the sample was 1400° C. The FWHM of the φ-scan,as determined by fitting a gaussian curve to one of the peaks is ˜6.5°.The FWHM of the peaks in this scan is indicative of the in-plane textureof the grains in the sample.

[0073]FIG. 35 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked in the rolling direction, for a Ni-13 at % Cr-0.03at % Mg alloy fabricated by rolling and annealing a compacted andsintered, powder metallurgy preform. The final annealing temperature ofthe sample was 1400° C. The peak is indicative of the out-of-planetexture of the sample. The FWHM of the ω-scan, as determined by fittinga gaussian curve to one of the peaks is ˜6.9°.

[0074]FIG. 36 shows a rocking curve (ω-scan) from 10° to 40° with thesample being rocked about the rolling direction, for a Ni-13 at %Cr-0.03 at % Mg alloy fabricated by rolling and annealing a compactedand sintered, powder metallurgy preform. The final annealing temperatureof the sample was 1400° C. The peak is indicative of the out-of-planetexture of the sample. The FWHM of the ω-scan, as determined by fittinga gaussian curve to one of the peaks is ˜7.9°.

DETAILED DESCRIPTION OF THE INVENTION

[0075] Note: As used herein, percentages of components in compositionsare atomic percent unless otherwise specified.

[0076] A new method for producing highly textured alloys has beendeveloped. It is well established in the art that high purity FCC metalscan be biaxially textured under certain conditions of plasticdeformation, such as rolling, and subsequent recrystallization. Forexample, a sharp cube texture can be attained by deforming Cu by largeamounts (90%) followed by recrystallization. However, this is possibleonly in high purity Cu. Even small amounts of impurity elements (i.e.,0.0025% P, 0.3% Sb, 0.18% Cd, 0.47% As, 1% Sn, 0.5% Be etc.) cansignificantly modify the deformation behavior and hence the kind andamount of texture that develops on deformation and recrystallization. Inthis invention, a method is described to texture alloys of cubicmaterials, in particular FCC metal based alloys. Alloys and compositecompositions resulting in desirable physical properties can be processedto form long lengths of biaxially textured sheets. Such sheets can thenbe used as templates to grow epitaxial metal/alloy/ceramic layers for avariety of applications.

[0077] The present invention has application especially in the making ofstrengthened substrates with magnetism less than that of pure Ni. For asubstance to have less magnetism than pure Ni implies that its Curietemperature is less than that of pure Ni. Curie temperature is known inthe art as the temperature at which a metal becomes magnetic. In thefollowing description, a material having less magnetism than that ofpure Ni implies a material having a Curie temperature at least 50° C.less than that of pure Ni.

[0078] Many device applications require good control of the grainboundary of the materials comprising the device. For example in hightemperature superconductors grain boundary character is very important.The effects of grain boundary characteristics on current transmissionacross the boundary have been very clearly demonstrated for Y123. Forclean, stochiometric boundaries, J_(c)(gb), the grain boundary criticalcurrent, appears to be determined primarily by the grain boundarymisorientation. The dependence of J_(c)(gb) on misorientation angle hasbeen determined by Dimos et al. [1] in Y123 for grain boundary typeswhich can be formed in epitaxial films on bicrystal substrates. Theseinclude [001] tilt, [100] tilt, and [100] twist boundaries [1]. In eachcase high angle boundaries were found to be weak-linked. The low J_(c)observed in randomly oriented polycrystalline Y123 can be understood onthe basis that the population of low angle boundaries is small and thatfrequent high angle boundaries impede long-range current flow. Recently,the Dimos experiment has been extended to artificially fabricated [001]tilt bicrystals in Tl₂Ba₂CaCu₂O_(X) [2], Tl₂Ba₂Ca₂Cu₃O_(X) [3],TlBa₂Ca₂Cu₂O_(X) [4], and Nd_(1.85)Ce_(0.15)CuO₄ [3]. In each case itwas found that, as in Y123, J_(c) depends strongly on grain boundarymisalignment angle. Although no measurements have been made on Bi-2223,data on current transmission across artificially fabricated grainboundaries in Bi-2212 indicate that most large angle [001] tilt [3] andtwist [5,6] boundaries are weak links, with the exception of somecoincident site lattice (CSL) related boundaries [5,6]. It is likelythat the variation in J_(c) with grain boundary misorientation inBi-2212 and Bi-2223 is similar to that observed in thewell-characterized cases of Y123 and Tl-based superconductors. Hence inorder to fabricate high temperature superconductors with very criticalcurrent densities, it is necessary to biaxially align essentially allthe grains. This has been shown to result in significant improvement inthe superconducting properties of YBCO films [7-10].

[0079] A method for producing biaxially textured substrates was taughtin previous U.S. Pat. Nos. 5,739,086, 5,741,377, 5,898,020, and5,958,599. That method relies on the ability to texture metals, inparticular FCC metals such as copper, to produce a sharp cube texturefollowed by epitaxial growth of additional metalceramic layers.Epitaxial YBCO films grown on such substrates resulted in high J_(c).However, in order to realize any applications, one of the areasrequiring significant improvement and modification is the nature of thesubstrate. The preferred substrate was made by starting with high purityNi, which is first thermomechanically biaxially textured, followed byepitaxial deposition of metal and/or ceramic layers. Because Ni isferromagnetic; the substrate as a whole is magnetic and this causesdifficulty in practical applications involving superconductors. A secondproblem is the thermal expansion mismatch between the preferredsubstrate and the oxide layers. The thermal expansion of the substrateis dominated by that of Ni which is quite different from most desiredceramic layers for practical applications. This mismatch can result incracking and may limit properties. A third problem is the limitation ofthe lattice parameter to that of Ni alone. If the lattice parameter canbe modified to be closer to that of the ceramic layers, epitaxy can beobtained far more easily with reduced internal stresses. This can reduceor prevent cracking and other stress-related defects and effects (e.g.delamination) in the ceramic films.

[0080] Although a method to form alloys starting from the textured Nisubstrate is also suggested in U.S. Pat. Nos. 5,739,086, 5,741,377,5,898,020, and 5,958,599, its scope is limited in terms of the kinds ofalloys that can be fabricated. This is because only a limited set ofelements can be homogeneously diffused into the textured Ni substrate.

[0081] A method for fabricating textured alloys was proposed in anotherprevious invention U.S. Pat. No. 5,964,966. The invention involved theuse of alloys of cubic metals such as Cu, Ni, Fe, Al and Ag for makingbiaxially textured sheets such that the stacking fault frequency, ν, ofthe alloy with all the alloying additions is less than 0.009. In case itis not possible to make an alloy with desired properties to have thestacking fault frequency less than 0.009 at room temperature, thendeformation can be carried out at higher temperatures where the ν isless than 0.009. However, that invention may be limited in the sharpnessof the texture which can be attained. This is because no specificcontrol on the starting material to fabricate the biaxially texturedalloys was given which results in a sharp biaxial texture. Moreover, thealloys fabricated using the methods described in the invention, resultin materials which have secondary recrystallization temperatures lessthan 1200° C. Once the secondary recrystallization temperature isreached, the substrate essentially begins to lose all its cube texture.Low secondary recrystallization temperatures limit the sharpness ofbiaxial texture that can be obtained and what deposition temperaturescan be used for depositing epitaxial oxide or other layers on suchsubstrates.

[0082] Furthermore, the invention does not teach how one couldpotentially texture and effectively use an alloy with compositions suchthat the stacking fault frequency of the alloy is greater than 0.009 atroom temperature. Lastly, the invention does not provide a method ordescribe an article which effectively incorporates ceramic constituentsin the alloy body to result in very significant mechanical toughening,yet maintaining the strong biaxial texture.

[0083] A metallic object such as a metal tape is defined as having acube texture when the [100} crystallographic planes of the metal arealigned parallel to the surface of the tape and the [100]crystallographic direction is aligned along the length of the tape. Thecube texture is referred to as the {100}<100> texture.

[0084] Here, a new method for fabricating strongly or dominantly cubetextured surfaces of composites which have tailored bulk properties(i.e. thermal expansion, mechanical properties, non-magnetic nature,etc.) for the application in question, and which have a stronglytextured surface that is compatible with respect to lattice parameterand chemical reactivity with the layers of the electronic device(s) inquestion, is described. Herein the term dominantly or strongly cubetextured surface describes one that has 95% of the grains comprising thesurface in the {100}<100> orientation.

[0085] oriented The method for fabricating biaxially textured alloys ofthe herein disclosed and claimed invention utilizes powder metallurgytechnology. Powder metallurgy allows fabrication of alloys withhomogeneous compositions everywhere without the detrimental effects ofcompositional segregation commonly encountered when using vacuum meltingor casting to make alloys. Furthermore, powder metallurgy allows easycontrol of the grain size of the starting alloy body. Moreover, powdermetallurgy allows a fine and homogeneous grain size to be achieved.Herein, fine grain size means grain size less than 200 microns.Homogeneous grain size means variation in grain size of less than 40%.In the following we break the discussion into three parts:

[0086] Procedures and examples to obtain biaxially textured alloys whichhave stacking fault frequencies less than 0.009 at room temperature, buthave better biaxial textures and have higher secondary recrystallizationtemperatures.

[0087] Procedures and examples to obtain biaxially textured alloys witha distribution of ceramic particles for mechanical strengthening.

[0088] Procedures and examples to obtain and effectively use biaxiallytextured alloys which have stacking fault frequencies greater than 0.009at room temperature.

Procedures and Examples to Obtain Biaxially Textured Alloys which HaveStacking Frequencies less than 0.009 at Room Temperature, but HaveBetter Biaxial Textures and Have Higher Secondary RecrystallizationTemperatures

[0089] The basic premise or idea here is that alloys are formed bystarting with high purity powders of the alloy constituents,mechanically mixing them together to form a homogeneous mixture,compacting and heat-treating the resulting body to form a raw article orstarting preform. The thermomechanical treatment results in a fine andhomogeneous grain size in the initial starting preform.

EXAMPLE I

[0090] Begin with a mixture of 80% Ni powder (99.99% purity) and 9% Wpowder. Mix and compact at appropriate pressures into a rod or billet.Then heat treat at 900° C. for 2 hr. The grain size at the end of heattreatment is less than 50 μm. Deform, by rolling, to a degree greaterthan 90% total deformation, preferably using 10% reduction per pass andby reversing the rolling direction during each subsequent pass. Annealat about 1200° C. for about 60 to produce a sharp biaxial texture.Annealing is performed in flowing 4% H₂ in Ar.

[0091]FIG. 1 shows a (111) X-ray diffraction pole figure of thebiaxially textured alloy substrate. As can be seen, only four peaks areevident. Each peak refers to one of four crystallographically similarorientations corresponding to {100}<100>, such that the (100) plane isparallel to the surface of the tape and <100> direction is aligned alongthe long axis of the tape. FIG. 2 shows a phi-scan of the [111]reflection showing the degree of in-plane texture. The FWHM of the tapeis determined by fitting a gaussian curve to the data is 8.8°. FIG. 3shows the rocking curve or the out-of-plane texture as measured byscanning the [200] reflection of the substrate. FIG. 3 is a rockingcurve with the sample being rocked in the rolling direction and shows aFWHM of 6.14°. FIG. 4 is a rocking curve with the sample being rockedabout the rolling direction and shows a FWHM of 8.49°. This is truly asingle orientation texture with all crystallographic axis being alignedin all direction within 8-9° Alloys made by procedures other than whatis described above result in secondary recrystallization at about 1200°C.

EXAMPLE II

[0092] Begin with a mixture of 80% Ni powder (99.99% purity) and 9% Wpowder. Mix and compact at appropriate pressures into a rod or billet.Then heat treat at 900° C. for 2 hr. The grain size at the end of heattreatment is less than 50 μm. Deform, by rolling, to a degree greaterthan 90% total deformation, preferably using 10% reduction per pass andby reversing the rolling direction during each subsequent pass. Annealat about 1400° C. for about 60 minutes to produce a sharp biaxialtexture. Annealing is performed in flowing 4% H₂ in Ar.

[0093]FIG. 5 shows a (111) X-ray diffraction pole figure of thebiaxially textured alloy substrate. As can be seen, only four peaks areevident. Each peak refers to one of four crystallographically similarorientations corresponding to {100}<100>, such that the (100) plane isparallel to the surface of the tape and <100> direction is aligned alongthe long axis of the tape. FIG. 6 shows a phi-scan of the [111]reflection showing the degree of in-plane texture. The FWHM of the tapeis determined by fitting a gaussian curve to the data is ˜6.3°. FIG. 7shows the rocking curve or the out-of-plane texture as measured byscanning the [200] reflection of the substrate. FIG. 7 is a rockingcurve with the sample being rocked in the rolling direction and shows aFWHM of 6.7°. FIG. 8 is a rocking curve with the sample being rockedabout the rolling direction and shows a FWHM of 7.5°. This is truly asingle orientation texture with all crystallographic axis being alignedin all direction within 6-7° Alloys made by procedures other than whatis described above result in secondary recrystallization at temperaturesmuch below 1400° C. and do not result in single orientation cube textureas shown in the pole figure of FIG. 5.

EXAMPLE III

[0094] Begin with a mixture of 87 at % Nickel powder (99.99% purity) and13% Chromium powder. Mix and compact at appropriate pressures into a rodor billet. Then heat treat at 900° C. for 2 hr. The grain size at theend of heat treatment is less than 50 □m. Deform, by rolling, to adegree greater than 90% total deformation, preferably using 10%reduction per pass and by reversing the rolling direction during eachsubsequent pass. Anneal at about 1200° C. for about 60 minutes toproduce a sharp biaxial texture. Annealing is performed in flowing 4% H₂in Ar.

[0095]FIG. 9 shows a (111) X-ray diffraction pole figure of thebiaxially textured alloy substrate. As can be seen, only four peaks areevident. Each peak refers to one of four crystallographically similarorientations corresponding to {100}<100>, such that the (100) plane isparallel to the surface of the tape and <100> direction is aligned alongthe long axis of the tape. FIG. 10 shows a phi-scan of the [111]reflection showing the degree of in-plane texture. The FWHM of the tapedetermined by fitting a gaussian curve to the data is ˜8.68°. FIG. 11shows the rocking curve or the out-of-plane texture as measured byscanning the [200] reflection of the substrate. FIG. 11 is a rockingcurve with the sample being rocked in the rolling direction and shows aFWHM of 5.83°. FIG. 12 is a rocking curve with the sample being rockedabout the rolling direction and shows a FWHM of 9.82°. This is truly asingle orientation texture with all crystallographic axis being alignedin all directions within 8-10°. Alloys made by procedures other thanwhat is described above result in secondary recrystallization at 1200°C.

EXAMPLE IV

[0096] Begin with a mixture of 87 at % Nickel powder (99.99% purity) and13% Chromium powder. Mix and compact at appropriate pressures into a rodor billet. Then heat treat at 900° C. for 2 hr. The grain size at theend of heat treatment is less than 50 □m. Deform, by rolling, to adegree greater than 90% total deformation, preferably using 10%reduction per pass and by reversing the rolling direction during eachsubsequent pass. Anneal at about 1400° C. for about 60 minutes toproduce a sharp biaxial texture. Annealing is performed in flowing 4% H₂in Ar.

[0097]FIG. 13 shows a (111) X-ray diffraction pole figure of thebiaxially textured alloy substrate. As can be seen, only four peaks areevident. Each peak refers to one of four crystallographically similarorientations corresponding to {100}<100>, such that the (100) plane isparallel to the surface of the tape and <100> direction is aligned alongthe long axis of the tape. FIG. 14 shows a phi-scan of the [111]reflection showing the degree of in-plane texture. The FWHM of the tapedetermined by fitting a gaussian curve to the data is ˜6.1°. FIG. 15shows the rocking curve or the out-of-plane texture as measured byscanning the [200] reflection of the substrate. FIG. 15 is a rockingcurve with the sample being rocked in the rolling direction and shows aFWHM of 4.5°. FIG. 16 is a rocking curve with the sample being rockedabout the rolling direction and shows a FWHM of 7.3°. This is truly asingle orientation texture with all crystallographic axis being alignedin all directions within 6-7°. Alloys made by procedures other than thewhat is described above result in secondary recrystallization attemperatures much below 1400° C. and do not result in single orientationcube texture as shown in the pole figure of FIG. 13.

[0098] Similar experiments can be performed with binary alloys of Ni—Cu,Ni—V, Ni—Mo, Ni—Al, and with ternary alloys of Ni—Cr—Al, Ni—W—Al,Ni—V—Al, Ni—Mo—Al, Ni—Cu—Al. Similar results are also expected for 100%Ag and Ag alloys such Ag—Cu, Ag—Pd.

Procedures and Examples to Obtain Biaxially-Textured Alloys with aDistribution of Ceramic Particles for Mechanical Strengthening

[0099] Conventional wisdom and numerous experimental results indicatethat hard, ceramic particles are introduced or dispersed within a metalor alloy it results in significant mechanical strengthening. This arisesprimarily due to enhanced defect or dislocation generation should thismaterial be deformed. Conventional wisdom and prior experimental resultsalso indicate because of the presence of such hard, ceramic particles,and the enhanced defect generation locally at these particles, thedeformation is very inhomogeneous. Inhomogeneous deformation essentiallyprevents the formation of any sharp crystallographic texture. Hence,conventional wisdom and prior experimental results show that thepresence of even a very small concentration of ceramic particles resultin little texture formation even in high purity FCC metals such as Cuand Ni. Here we provide a method where ceramic particles can beintroduced in a homogeneous fashion to obtain mechanical strengtheningof the substrate, and still obtain a high degree of biaxial texture. Thekey is to have a particle size of less than 1 μm and uniformdistribution of the ceramic particles in the final preform, prior to thefinal rolling to obtain biaxial texture.

EXAMPLE V

[0100] Begin with a mixture of 0.03 at % Mg and remaining Ni powder. Mixand compact at appropriate pressures into a rod or billet. Then heattreat at 900° C. for 2 hr. During this thermomechanical processing allthe Mg is converted to MgO and it is dispersed in a fine and homogeneousmanner throughout the preform. The grain size at the end of heattreatment is less than 50 □m. Deform, by rolling, to a degree greaterthan 90% total deformation, preferably using 10% reduction per pass andby reversing the rolling direction during each subsequent pass. Annealat about 1200° C. for about 60 minutes to produce a sharp biaxialtexture. Annealing is performed in flowing 4% H₂ in Ar.

[0101]FIG. 17 shows a (111) X-ray diffraction pole figure of thebiaxially textured, particulate, composite substrate. As can be seen,only four peaks are evident. Each peak refers to one of fourcrystallographically similar orientations corresponding to {100}<100>,such that the (100) plane is parallel to the surface of the tape and<100> direction is aligned along the long axis of the tape. FIG. 18shows a phi-scan of the [111] reflection showing the degree of in-planetexture. The FWHM of the tape determined by fitting a gaussian curve tothe data is ˜8.68°. FIG. 19 shows the rocking curve or the out-of-planetexture as measured by scanning the [200] reflection of the substrate.FIG. 19 is a rocking curve with the sample being rocked in the rollingdirection and shows a FWHM of 7.92°. FIG. 20 is a rocking curve with thesample being rocked about the rolling direction and shows a FWHM of9.20°. This is truly a single orientation texture with allcrystallographic axis being aligned in all directions within 8-10°.Alloy substrates made by procedures other than what is described aboveundergo secondary recrystallization at such annealing temperatures andlose most of their biaxial texture. On the contrary, the substratesreported here improve their biaxial textures upon annealing attemperatures as high as 1400° C.

EXAMPLE VI

[0102] Begin with a mixture of 0.03 at % Mg, 9 at % W and remaining Nipowder. Mix and compact at appropriate pressures into a rod or billet.Then heat treat at 900° C. for 2 hr. During this thermomechanicalprocessing all the Mg is converted to MgO and it is dispersed in a fineand homogeneous manner throughout the preform. The grain size at the endof heat treatment is less than 50 □m. Deform, by rolling, to a degreegreater than 90% total deformation, preferably using 10% reduction perpass and by reversing the rolling direction during each subsequent pass.Anneal at about 1200° C. for about 60 minutes to produce a sharp biaxialtexture. Annealing is performed in flowing 4% H₂ in Ar.

[0103]FIG. 21 shows a (111) X-ray diffraction pole figure of thebiaxially textured, particulate, composite substrate. As can be seen,only four peaks are evident. Each peak refers to one of fourcrystallographically similar orientations corresponding to {100}<100>,such that the (100) plane is parallel to the surface of the tape and<100> direction is aligned along the long axis of the tape. FIG. 22shows a phi-scan of the [111] reflection showing the degree of in-planetexture. The FWHM of the tape determined by fitting a gaussian curve tothe data is ˜9.05°. FIG. 23 shows the rocking curve or the out-of-planetexture as measured by scanning the [200] reflection of the substrate.FIG. 23 is a rocking curve with the sample being rocked in the rollingdirection and shows a FWHM of 7.2°. FIG. 24 is a rocking curve with thesample being rocked about the rolling direction and shows a FWHM of9.04°. This is truly a single orientation texture with allcrystallographic axis being aligned in all directions within 8-10°.Alloy substrates made by procedures other than what is described aboveundergo secondary recrystallization at such annealing temperatures andlose most of their biaxial texture. On the contrary, the substratesreported here improve their biaxial textures upon annealing attemperatures as high as 1400° C.

EXAMPLE VII

[0104] Begin with a mixture of 0.03 at % Mg, 9 at % W and remaining Nipowder (99.99% purity). Mix and compact at appropriate pressures into arod or billet. Then heat treat at 900° C. for 2 hr. During thisthermomechanical processing all the Mg is converted to MgO and it isdispersed in a fine and homogeneous manner throughout the preform. Thegrain size at the end of heat treatment is less than 50 μm. Deform, byrolling, to a degree greater than 90% total deformation, preferablyusing 10% reduction per pass and by reversing the rolling directionduring each subsequent pass. Anneal at about 1400° C. for about 60minutes to produce a sharp biaxial texture. Annealing is performed inflowing 4% H₂ in Ar.

[0105]FIG. 25 shows a (111) X-ray diffraction pole figure of thebiaxially textured alloy substrate. As can be seen, only four peaks areevident. Each peak refers to one of four crystallographically similarorientations corresponding to {100}<100>, such that the (100) plane isparallel to the surface of the tape and <100> direction is aligned alongthe long axis of the tape. FIG. 26 shows a phi-scan of the [111]reflection showing the degree of in-plane texture. The FWHM of the tapeis determined by fitting a gaussian curve to the data is 6.1°. FIG. 27shows the rocking curve or the out-of-plane texture as measured byscanning the [200] reflection of the substrate. FIG. 27 is a rockingcurve with the sample being rocked in the rolling direction and shows aFWHM of 6.7°. FIG. 28 is a rocking curve with the sample being rockedabout the rolling direction and shows a FWHM of 7.5°. This is truly asingle orientation texture with all crystallographic axis being alignedin all direction within 6-7°. Alloy substrates made by procedures otherthan what is described above undergo secondary recrystallization at suchannealing temperatures and lose most of their biaxial texture. On thecontrary, the substrates reported here, improve their biaxial texturesupon annealing at temperatures as high as 1400° C.

EXAMPLE VIII

[0106] Begin with a mixture of 0.03 at % Mg, 13 at % Cr and remaining Nipowder. Mix and compact at appropriate pressures into a rod or billet.Then heat treat at 900° C. for 2 hr. During this thermomechanicalprocessing all the Mg is converted to MgO and it is dispersed in a fineand homogeneous manner throughout the preform. The grain size at the endof heat treatment is less than 50 μm. Deform, by rolling, to a degreegreater than 90% total deformation, preferably using 10% reduction perpass and by reversing the rolling direction during each subsequent pass.Anneal at about 1200° C. for about 60 minutes to produce a sharp biaxialtexture. Annealing is performed in flowing 4% H₂ in Ar.

[0107]FIG. 29 shows a (111) X-ray diffraction pole figure of thebiaxially textured, particulate, composite substrate. As can be seen,only four peaks are evident. Each peak refers to one of fourcrystallographically similar orientations corresponding to {100}<100>,such that the (100) plane is parallel to the surface of the tape and<100> direction is aligned along the long axis of the tape. FIG. 30shows a phi-scan of the [111] reflection showing the degree of in-planetexture. The FWHM of the tape determined by fitting a gaussian curve tothe data is ˜8.06°. FIG. 31 shows the rocking curve or the out-of-planetexture as measured by scanning the [200] reflection of the substrate.FIG. 31 is a rocking curve with the sample being rocked in the rollingdirection and shows a FWHM of 5.1°. FIG. 32 is a rocking curve with thesample being rocked about the rolling direction and shows a FWHM of9.47°. This is truly a single orientation texture with allcrystallographic axis being aligned in all directions within 8-10°.Begin with a mixture of 0.03 at % Mg, 9 at % W and remaining Ni powder(99.99% purity). Mix and compact at appropriate pressures into a rod orbillet. Then heat treat at 900° C. for 2 hr. During thisthermomechanical processing all the Mg is converted to MgO and it isdispersed in a fine and homogeneous manner throughout the preform. Thegrain size at the end of heat treatment is less than 50 μm. Deform, byrolling, to a degree greater than 90% total deformation, preferablyusing 10% reduction per pass and by reversing the rolling directionduring each subsequent pass. Anneal at about 1400° C. for about 60minutes to produce a sharp biaxial texture. Annealing is performed inflowing 4% H₂ in Ar.

EXAMPLE IX

[0108] Begin with a mixture of 0.03 at % Mg, 13 at % Cr and remaining Nipowder (99.99% purity). Mix and compact at appropriate pressures into arod or billet. Then heat treat at 900° C. for 2 hr. During thisthermomechanical processing all the Mg is converted to MgO and it isdispersed in a fine and homogeneous manner throughout the preform. Thegrain size at the end of heat treatment is less than 50 μm. Deform, byrolling, to a degree greater than 90% total deformation, preferablyusing 10% reduction per pass and by reversing the rolling directionduring each subsequent pass. Anneal at about 1400° C. for about 60minutes to produce a sharp biaxial texture. Annealing is performed inflowing 4% H₂ in Ar.

[0109]FIG. 33 shows a (111) X-ray diffraction pole figure of thebiaxially textured alloy substrate. As can be seen, only four peaks areevident. Each peak refers to one of four crystallographically similarorientations corresponding to {100}<100>, such that the (100) plane isparallel to the surface of the tape and <100> direction is aligned alongthe long axis of the tape. FIG. 34 shows a phi-scan of the [111]reflection showing the degree of in-plane texture. The FWHM of the tapeis determined by fitting a gaussian curve to the data is ˜6.5°. FIG. 35shows the rocking curve or the out-of-plane texture as measured byscanning the [200] reflection of the substrate. FIG. 35 is a rockingcurve with the sample being rocked in the rolling direction and shows aFWHM of 6.9°. FIG. 36 is a rocking curve with the sample being rockedabout the rolling direction and shows a FEW of 7.9°. This is truly asingle orientation texture with all crystallographic axis being alignedin all direction within 6-8°. Alloy substrates made by procedures otherthan what is described above undergo secondary recrystallization at suchannealing temperatures and lose most of their biaxial texture. On thecontrary, the substrates reported here, improve their biaxial texturesupon annealing at temperatures as high as 1400° C.

EXAMPLE X

[0110] Begin with 99.99% pure Ni powder, and mix in fine(nanocrystalline or microcrystalline) oxide powders such as CeO₂, Y₂O₃,and the like. Mix homogeneously and compact to a monolithic form.Deform, preferably by reverse rolling to a degree of deformation greaterthan 90%. Heat treat at temperatures above the primary recrystallizationtemperature but below the secondary recrystallization temperature toobtain a sharp biaxially textured substrate.

[0111] Similar experiments with additions of a dispersion and at leastone fine metal oxide powder such as but not limited to Al₂O₃, MgO, YSZ,CeO₂, Y₂O_(3,), YSZ, and RE₂O₃; etc. can be performed with binary alloysof Ni—Cu, Ni—V, Ni—Mo, Ni—Al, and with ternary alloys of Ni—Cr—Al,Ni—W—Al, Ni—V—Al, Ni—Mo—Al, Ni—Cu—Al. Similar results are also expectedfor 100% Ag and Ag alloys such Ag—Cu, Ag—Pd.

Procedures and Examples to Obtain and Effectively Use Biaxially TexturedAlloys which Have Stacking Fault Frequencies Greater than 0.009 at RoomTemperature

[0112] In all the following examples, begin with separate powders of theconstituents required to form the alloy, mixing them thoroughly andcompacting them preferably into the form or a rod or billet. The rod orbillet is then deformed, preferably by rolling, at about roomtemperature or a higher temperature provided the higher temperature islow enough that negligible inter-diffusion of elements occurs. Duringthe initial stages of deformation the larger metal constituentessentially forms a connected and mechanically bonded network. The rodor billet is now rolled to a large degree of deformation, preferablygreater than 90%. The alloying element powders remain as discreteparticles in the matrix and may not undergo any significant deformation.Once the deformation is complete, rapidly thermally re-crystallize thesubstrate to texture the matrix material. The alloying elements can bediffused in at a higher temperature after the texture is attained in thematrix.

EXAMPLE XI

[0113] Begin with 80% Ni and 20% Cr powder. Mix homogeneously andcompact to a monolithic form. Heat-treat to low temperatures so as tobond Ni—Ni particles. Since Cr particles are completely surrounded byNi, their sintering or bonding to the Ni particles is not critical.Deform, preferably by reverse rolling to a degree of deformation greaterthan 90%. In such a case, the final substrate does not have ahomogeneous chemical composition. There are clearly Cr particlesdispersed in the matrix. The substrate is now rapidly heated in afurnace to a temperature between the primary and secondaryrecrystallization of Ni. The objective is to obtain a cube texture inthe Ni matrix, with local regions of high Cr concentrations. The aim ofthe heat treatment is to minimize diffusion of Cr into the Ni matrix.Once the cube texture has been obtained, desired epitaxial oxide,nitride or other buffer layers are deposited on the substrate. Once thefirst layer is deposited, the substrate can be heat treated at highertemperatures to affect diffusion of Cr into Ni. While highconcentrations of Cr of 20 at % in the substrate would result inappearance of secondary texture components, it does not matter at thispoint what the texture of the underlying metal below the texturedceramic buffer layer is, since further epitaxy is going to occur at thesurface of the first ceramic layer.

[0114] Similar experiments can be performed with binary alloys of Ni—Cu,Ni—V, Ni—Mo, Ni—Al, and with ternary alloys of Ni—Cr—Al, Ni—W—Al,Ni—V—Al, Ni—Mo—Al, Ni—Cu—Al. Similar results are also expected for 100%Ag and Ag alloys such Ag—Cu, Ag—Pd.

[0115] Similar experiments can also be performed with additions of adispersion of at least one fine metal oxide powder such as but notlimited to Al₂O₃, MgO, YSZ, CeO₂, Y₂O_(3,), YSZ, and RE₂O₃; etc. withbinary alloys of Ni—Cu, Ni—V, Ni—Mo, Ni—Al, and with ternary alloys ofNi—Cr—Al, Ni—W—Al, Ni—V—Al, Ni—Mo—Al, Ni—Cu—Al. Similar results are alsoexpected for 100% Ag and Ag alloys such Ag—Cu, Ag—Pd.

[0116] While there has been shown and described what are at presentconsidered the preferred embodiments of the invention, it will beobvious to those skilled in the art that various changes andmodifications can be made therein without departing from the scope ofthe inventions defined by the appended claims.

What is claimed is:
 1. A strengthened, biaxially textured alloy articlehaving a magnetism less than pure Ni comprising a rolled and annealed,compacted and sintered powder-metallurgy preform article, the preformarticle having been formed from a powder mixture selected from the groupof mixtures consisting of: Ni, Ag, Ag—Cu, Ag—Pd, Ni—Cu, Ni—V, Ni—Mo,Ni—Al, Ni—Cr—Al, Ni—W—Al, Ni—V—Al, Ni—Mo—Al, Ni—Cu—Al; and at least onefine metal oxide powder; the article having a grain size which is fineand homogeneous; and having a dominant cube oriented {100}<100>orientation texture; and further having a Curie temperature less thanthat of pure Ni; the article further comprising at least one layerhaving superconducting properties.